The Victorian Marine Safety web site probably has the best write up on kayak safety in my opinion its well worth a look. Marine Safety Victoria
A couple of examples of jackets
There are so many different type of jackets out there. But if you follow the safety guidelines of the various state bodies you will be well on the way to selecting the correct rating jacket for where you are and what you want to do.
Part of safety also in my opinion is the have a paddle leash, you don't want that paddle floating off Also the old Be Seen Be Safe saying is a good one to remember..